Tongue rail locking mechanism



Sept. 29, 1959 TAKUJI UEDA TONGUE RAIL LOCKING MECHANISM 3 Sheets-Sheet1 Filed Oct. 19, 1955 Fig. 3

Sept. 29, 1959 Filed Oct. 19, 1955 TAKUJI UEDA 2,906,477 TONGUE RAILLOCKING MECHANISM 3 Sheets-Sheet 2 nil Sept. 29, 1959 TAKUJI UEDA2,906,477

TONGUE RAIL LOCKING MECHANISM Filed Oct 19, 1955 s Sheets-Sheet s F g- 3Y United States Patent 7 2,906,477 I TONGUE RAIL LOCKING MECHANISMTakuji Ueda, Setagaya-ku, Tokyo, Japan Application October 19, 1955,Serial No. 541,476

Claims priority, application Japan October 22, 1954 9 Claims. (Cl.246-318) This invention relates to improvements of locking mechanisms tomaintain the contact of a tongue rail with a stock rail firmly by meansother than a spring.

In a conventional spring switch mechanism, the tongue rail is pressedagainst the stock rail by means of a spring and, when a train passesover the switch, the assembly is spread out by the flanges of the carwheels of the train in order that the train may pass safely. However,traflic accidents may happen where the tongue rail is in contact withthe stock rail only by means of a spring, because repeated openingmotions of the tongue rail may occur due to shock caused by the passingof a high speed train.

An object of this invention is to provide an improved locking mechanismfor a point switch; that is, for fixing a tongue rail to a stock rail byutilizing a dead-point alignment of a link mechanism in order to assurethe locking thereof.

A feature of this invention is to provide a spring switch lever with atongue rail locking mechanism.

Another feature is to provide a spring switch mechanism with a tie barincorporated with the said locking mechanism.

Still another feature of this invention is to provide a complete lockingmechanism which, by eliminating excessive stress on the link assembly inthe said tongue rail locking mechanism, prevents a failure thereof whena train passes over it.

The accompanying drawings illustrate the embodiments of this invention.

In the drawing:

Figure l is a plan view of a part of a rail arrangement showing oneexample of its application;

Figure 2 is a similar plan view showing another feature;

Figure 3 is a skeleton diagram of the principal mechanism;

Figure 4 is a diagrammatic illustration with a train spreading thetongue rail;

Figure 5 shows a plan view of still another embodiment of thisinvention, including a special tie bar;

Figure 6 is a plan view of an embodiment with another special tie bar;

Figure 7 is a sectional view of the tie bar in Figure 6, and takenthrough line 7-7;

Figure 8 is an enlarged partial sectional view of a connecting linkshown in Figure 6;

Figure 9 is a similar plan view showing another 'em bodiment of thisinvention; and

Figure 10 is an enlarged partially sectional view of the connecting linkreferred to in Figure 9. i

In Figure 1, elements 11 and 12 are the stock rails of a track and 13and 14 the tongue rails. A rectangular bell crank is pivoted on the axle17 at the center line of the track on a bed plate 16 which is fixed onthe sleeper, the end of each arm 18A, 18B of the bell crank beingconnected to the inward transverse projections 19A, 19B of the tonguerail 13, 14 by links 20A and 20B re spectively. The locking mechanism isof the same strucseen in Figure 4, an allowance equal to the maximum,

ture on both side tongue rails except as particularly defined. When oneof the tongue rails for example, rail 13 (the right one) contacts thestock rail 11, as shown in the drawing, the right arm 18A of the bellcrank and the projection 19A of the tongue rail 13 are so arranged thatthey make a straight line together with the right link 20A perpendicularto the tongue rail 13. Hence, the tendency for the said tongue rail topart from the stock rail is completely prevented by the dead-pointalignment of the said three elements. The provision of a spring 21, intension, one end of which is connected at the center line of the trackto the plate 16 and the other on the bell crank middle arm 18C, willmake the above feature even more efiective, strengthening thecounterclockwise movement of the bell crank.

The middle or the third arm 18C is rigidly connected to the bearing orhub portion of the bell crank as an integral part of it, one end ofwhich is connected to the switch lever by means of a connecting rod 22.By a turn: ing of the switch lever in the opposite direction, theconnecting rod 22 is pulled leftwards in Figure 1, easily reversing thedirection of the arms 18A, 18B by the turning of the bell crank. Theleft tongue rail 14 then contacts the left stock rail 12, arranging theabove three elements in a dead-point alignment, and further spacing andkeeping the right tongue rail 13 apart from the stock rail 11. As in thefirst case, this alignment absolutely prevents the unlocking of the lefttongue rail 14, and a train can pass safely.

Another embodiment of this invention is illustrated in Figure 2. Here,the said bell crank is pivoted about the axle 23 on the opposite side ofthe sleeper and the tongue rails 13 and 14 are connected by the tie bar24, which is connected to the connecting rod 25 of the switch. Theswitching is actuated by the transverse motion of the said tie bar as inthe ordinary type. In this case, the spring 21 acts in compression toturn the bell crank.

In both cases mentioned above, however, the bell crank need notnecessarily be rectangular, and the said deadpoint alignment is as wellapplicable to cases where a separate crank lever is employed for each ofthe tongue rails respectively.

In the second example, when the tongue rails 13 and 14 are switched tothe left by the tie bar 24, the turning of the rectangular bell crankwill eflect a much bigger movement of the left tongue rail and less onthe right where the rotational angle 0 of the bell crank is smaller thanthe 45 as shown in Figure 3. Hence, if the tie bar is fixed rigidly tothe tongue rails 13 and 14, it can easily be realized that tensile orshearing stress occurs in the structural members and this may causetrouble.

In the spreading out of the tongue rail by a train as difference betweenthe displacements a and b of the tongue-rail is made between the tonguerails 13 and 14 and the tie bar 24. vThe connecting plates 26 and 27 arefixed on the insides of the tongue rails 13 and 14 and pins 30 and 31are inserted slidably in slots 28 and 29 of the connecting plates. Pins30 and 31 on the tie bar 24 are located at the outer ends of the slots28 and 29, respectively, as shown in Figure 2.

In Figure 2, in the first stage of the leftward movement of the tiebar'24 by the switch lever, though the leftward movement of the righttongue rail 13'caused by counter-clockwise rotation of the bell crank iscomparatively smaller than that of the left tongue rail, no'compulsoryforce will act on the right tongue rail at the slow leftward movement ofit, because the right side pin 30 of the tie bar 40 can move freelyalong the slot 28. As the angle 0 is increased to more than 45 theefiect of the bell crank on the movement of the tongue rails will becompletely reversed, but due to the free rightward movement of the pin31 in the left side slot 29, there will occur no undesirable stress. Theright tongue rail will be moved to the left safely, and thus theswitching of the tongue rail will be very smooth.

Figure 5 shows another embodiment of this invention. Here, the tonguerail 13 is normally in contact with the right stock rail 11 by the forceof the compression spring 32 as in an ordinary spring switch. At thesame time, as seen in the former examples, the right arm 18A of the bellcrank and the link 20A and the inward projection 19A of the right tonguerail are so arranged on a deadpoint alignment, as to prevent the righttongue rail 13 from getting out of order and to keep it normalnotwithstanding the effect of any undesirable vibration of the springcaused by the shock of a passing train. Hence, in order to compensatefor the difference between the displacement of the right and left tonguerails 13 and 14 caused by the turning of the bell crank, the tie bar isinterlocked with the switch in the following way. The tie bar 24 isrigidly fixed only to the right tongue rail 13 by the pin 33, andconnected particularly to the left tongue rail by the second pin 35which is freely slidable in the slot 34 of the connecting plate 27, saidpin 35 being at the left end of the slot 34 at a normal position asshown in Figure 5. When the trailing train arrives, as shown in Figure4, the left tongue rail 14 is spread out by the flanges of the wheels ofthe train and the bell crank is turned counter-clockwise by means of thelink 20B. In the first stage of this rotation, the leftward displacementof the left arm 18B of the bell crank is comparatively larger than thatof the right arm 18A, so the movement of the left tongue rail 14 is notthe same as that of the right tongue rail 13; however, as the lefttongue rail 14 is connected slidably with the pin 35 set on the tie barby the slot 34 of the connecting plate 27, the larger displacement ofthe left tongue rail is absorbed by the rightward movement of the secondpin 35 in the slot 34. In the latter stage of the counter-clockwise turnof the bell crank, though the displacement of the tongue rails will bereversed, the smaller displacement of the left arm 1813 in this case iscompensated for by the leftward sliding of the second pin 35 in the slot34; thus without giving any undesirable stress on the structuralmembers, the left tongue rail 14 will be held in its required positiontaking a dead-point alignment where the straight line through the leftlink 20B and the arm 18B of the bell crank may pass the pivot 23 of thebell crank, as will be easily understood from the above explanation, andis locked firmly. After the train has passed, the bar 24 is displaced tothe right by the force of the compres sion spring 32 of the switch, andturns the bell crank clockwise. In the first stage of this movement, thedisplacement of the right link 18B is larger than that of the left link18B, but the second pin 35 on the tie bar 24 slides to the left freelyin the slot 34 of the connecting plate 27 and exerts no undesirabletension on the left tongue rail 14. In the latter stage too, though thesituation is reversed, it will be readily understood that no troublewill occur.

In the above-mentioned embodiments, the connection of the tie bar withthe tongue rail is made by means of pins; but it is not alwaysdesirable, because of structural strength, to transmit the moving powerto the tongue rail by means of pin or bolt joints. In Figure 6 andFigure 7, straps 36 and 37 are attached on the tie bar 24 andbutt-jointed to the inward ends of the connecting plates 26 and 27,which are provided on the insides of the tongue rails 13 and 14 as inthe former instances. Accordingly, the movement of the connecting rod 25and the tie bar 24 to the left, by the operation of the switch lever,will cause the left strap 37 to push leftward the left tongue rail andmake the bell crank turn counterclockwise. In the first stage of thisrotation, the movement of the right tongue rail 13 to the left is not somuch as that of the left tongue rail 14, but as the right strap 36 ofthe tie bar 24 abuts only on the inside of the connecting plate 26 ofthe right tongue rail 13, the leftward movement of the tie bar 24 doesnot positively pull the right tongue rail 13, and so, even if the slowmovement of the right tongue rail 13 is so retarded that it does notfollow the movement of the tie bar 24, there will be only a simple slipand no stress between the tie bar and the right tongue rail. In thelatter half of the counter-clockwise rotation of the bell crank, theright tongue rail 13 moves faster than the left tongue rail 14, so as tocompensate for the gap between the right strap 36 and the connectingplate 26 of the right tongue rail 13 caused by the slip in the firsthalf, and no trouble will occur. The bolts 38 in the joint of the aboveillustration, Figure 7, serve only to guide the slip.

In the reverse operation of the switch, everything will operate inreverse order to the above. In short, as the movement between the tiebar and the tongue rail is transmittted by means of a butt-joint and notby bolts, the reliability of the mechanism is assured by avoidingfailure of the bolts caused by an excessive shearing stress.

It is to be noticed that the tongue rail 13 is pressed strongly againstthe stock rail 11 by the flanges of the wheels when a train passes. Ingeneral, the total length of the arm 18A of the connecting rod 20A andof the Figure 6 and Figure 8, an expansion joint is fitted on the saidthree parts, an example of which is shown in Figure 8; that is, theconnecting link is composed of a connecting rod 20A, a threaded bolt 40which is freely inserted into the connecting rod 20A, a compressionspring 39 mounted between the connecting rod 20A and a cap 41 fixed atthe end of the threaded bolt 40, and a nut 42 is screwed on the bolt 40abutting the end of the rod 20A, so that it prevents the bolt 40 fromentering fully into the connecting rod 20A. A washer 43 and second nut44 lock the first nut 42 on the bolt 40; as the length of the bolt 40inserted in the connecting rod 20A can be adjusted by means of the firstnut 42 after a loosening of the second nut 44, the length of the totallink members may be adjusted easily when laying down the railway track,so as to allow the tongue rail 13 to be forced against the stock rail 11when desired.

Another embodiment of this invention, particularly provided with adevice for absorbing the effect of the excessive pressure of the tonguerail on the stock rail, is shown in Figures 9 and 10. In thisembodiment, the connecting member is composed of two pieces, onethreaded bolt 20A1 and a yoke 20A2. A pin 44 set on the yoke 20A2 isinserted slidably into a slot 45 provided at the end of the transverseprojection 19A. When the elements 18A, 20A1, 20A2 and 19A are secured asin above embodiments, the projection 19A on the tongue rail 13 cannotmove leftwards, as the pin 44 abuts on the right end of the slot 45;that is to say, the tongue rail 13 is locked against vibration, but whenit is pressed on the stock rail 11 by a passing train, the projection19A can be deviated a little to the right owing to the pin 44 sliding inthe slot 45.

This construction has the advantages of avoiding excessive tensilestress on the dead-point alignment of the assembly as the tongue rail isforced against the stock rail by the passing train.

What is claimed is:

1. In a rail arrangement including spaced and parallel stock railsdefining a center line therebetween, and tongue rails between the stockrails and spaced such that only one tongue rail can contact a stock railat one time; apparatus comprising a stationary plate between the stockrails, a bell crank member pivoted on the plate at the center line andincluding two angularly spaced arms, first and second means respectivelyconnected to the tongue rails, a link coupling one arm to said firstmeans, and another link coupling the other arm to said second means, acontrol member connected with the bell crank member for controllablypivoting the same between two extreme positions, and a spring coupled tosaid plate at the center line and to said bell crank member at a pointwhich crosses the center line with the bell crank member being pivotedfrom one extreme position to the other whereby pivotal motion of thebell crank member is resisted, the lengths of said links being suchthat, with a tongue rail engaging a stock rail, the associated arm, linkand means and pivot point of the bell crank lever are linearly alignedto supplement the action of said spring.

2. Apparatus as claimed in claim 1 comprising n'urther spring means forloading each of said tongue rails to maintain the rail normally incontact with the stock rail biassed toward said stock rail.

3. Apparatus as claimed in claim 1 comprising a tie bar, means on thetongue rails adapted for engaging the tie bar, and connections betweenthe latter said means and the tie bar, at least one of said connectionsbeing a lost motion connection.

4. Apparatus as claimed in claim 3 wherein all connections are lostmotion connections.

5. Apparatus as claimed in claim 3 wherein the latter said means andsaid tie bar collectively comprise pins and define elongated slotsaccommodating said pins.

6. Apparatus as claimed in claim 3 wherein the latter vsaid means areplates detachably engaging the tongue rails, said connections comprisingstraps on the tie bars for loosely engaging the latter said plates andbolts on the tie bars for guiding the latter said plates into engagementwith the straps.

7. Apparatus as claimed in claim 3 wherein said links comprise means foradjusting their respective lengths.

8. Apparatus as claimed in claim 3 wherein said links are resilientmembers for facilitating the linear alignment.

9. Apparatus as claimed in claim 8 wherein said links include adjustmentmeans for adjusting their respective resiliencies.

References Cited in the file of this patent UNITED STATES PATENTS965,243 Snow July 26, 1910 1,509,777 Qualls Sept. 23, 1924 2,375,890Black May 15, 1945 FOREIGN PATENTS 7,666 Australia May 3, 1933 81,237Austria Sept. 10, 1920 662,298 France Mar. 18, 1929 7,716 Germany Dec.16, 1879 14,520 Netherlands May 15, 1926

